That’s weird. I coulda sworn that’s where I read it. I was just reading that wiki article recently, so I just posted the link without bothering to reread it. I must have read it somewhere else. But I distinctly remember reading somewhere that Kittenger is the only person ever to have broken the sound barrier without being in some sort of conveyance (rocket, plane, car, etc.).
[quote=“md2000, post:16, topic:530266”]
There was a bomb developed for the Gulf War (I or II?) which was designed to take the deeply buried bunkers used by the Iraqi high command. It had to go through 50 feet of dirt or gravel then a few feet of reinforced concrete. According to Time Magazine, some wag at the munitions plant even painted the name on it, “The Saddamizer”. It had a time delay fuse, a nose cone that was 25 feet of solid steel and was dropped from 50,000 feet. I wonder if that hit supersonic speeds? quote]
Bomb used in Desert Storm described below. Made from surplus 8" artillery tubes, not 28 feet of steel (probably misplaced from the GBU-28 nomenclature.
Description
The Guided Bomb Unit-28 (GBU-28) is a special weapon developed for penetrating hardened Iraqi command centers located deep underground. The GBU-28 is a 5,000-pound laser-guided conventional munition that uses a 4,400-pound penetrating warhead. The bombs are modified Army artillery tubes, weigh 4,637 pounds, and contain 630 pounds of high explosives. They are fitted with GBU-27 LGB kits, 14.5 inches in diameter and almost 19 feet long. The operator illuminates a target with a laser designator and then the munition guides to a spot of laser energy reflected from the target.
The GBU-28 ““Bunker Buster”” was developed specifically to destroy Iraqi underground hardened command bunkers during the Gulf War. Scratch built from a section of surplus 8"" howitzer barrel filled with 600 pounds of explosives, the 5,000 pound GBU-28 is capable of penetrating more than 20 feet of reinforced concrete and deeper than 100 feet underground. Equipped with essentially the same guidance hardware as the GBU-10 Paveway II, the GBU-28 is capable of hitting discrete, hardened targets deep underground. The GBU-28 was successfully used twice during the Gulf War, with each of the weapons being released by FB-111F Aardvarks for use against buried command bunkers.
That would make sense only if the bomb were moving past you.
If you were on the ground, you wouldn’t hear low-to-high or high-to-low. You would hear faint-to-loud.
Conversely, The bombardier would hear loud-to-faint, as the bomb wouldn’t move past him either.
IIRC, first and maybe second generation laser-guided smart bombs (such as the ones used in the Gulf War) made a “clicking” noise, because the guidance fins would snap back and forth (ie: all the way left, all the way right, all the way left, all the way right) like a group of cartoon firemen trying to catch a swerving-in-midair person with a safety net. The clicks came from the fins hitting the stops at either end of their range of movement.
Later generations of the smart bombs had fins that could make more subtle adjustments, so now you don’t hear the clickclickclickclick sound anymore.
Also, IIRC, the dive flaps on the Douglas SBD Dauntless (“Slow But Deadly”) dive bomber had holes cut in it as part of their design (I think it was to help slow the plane in a dive without stopping the airflow entirely). A side-effect of the design was that the SBD Dauntless had a banshee-like scream. That had to be a terribly un-nerving sound to hear from the deck of a ship at sea.
No. The bomb reaches terminal velocity fairly early, especially one with a high drag tail that would be likely to whistle much at all. To a person some distance from the impact point, it is approaching quickly when still at high altitude. As it nears the ground, the approach speed decreases to zero, thus decreasing Doppler shift.